Extension-ladder



(No Model.)

W. J. ROBERTSON & J. B. GENIN. EXTENSION LADDER.

No. 478.969. Patented'July 12, 1892.

QX- vbm-woao I Z I I ezg g fig Wz/ $23 2 6 72; W ?7 MZ I, 7 6M%% UNITED STATES PATENT OFFICE.

WILLIAIWI J. ROBERTSON AND JOHN B. GENIN, OF ST. ALBANS, ASSIGNORS TO THEMSELVES AND EDWIN L. RIPLEY, OF BURLINGTON, VERMONT.

EXTENSION-LADDER.

SPECIFICATION forming part of Letters Patent No. 478,969, dated July 12, 1892.

Application filed June 10, 1890. Serial No. 354,935- (No model.)

T on whom it may concern.-

Be it known that we, WVILLIAM J. ROBERT- SON and JOHN B. GENIN, citizens of the United States of America, residing at the city of St. Albans, in the county of Franklin and State of Vermont, have invented a new and useful Improved Extension-Ladder, of which the followingis a full, clear, and exact description.

The present invention has relation to that class of extension-ladders wherein are employed one or more extensible ladder-sections and means for elevating such section and holding it in its adjusted position with relation lg to the ladder-section which rests upon the ground.

It is the object of the present invention to improve the device heretofore in use for bolding and supporting the movable ladder-section in its extended or adjusted position, whereby it will be more firmly held in place and a wide tread secured by having all the rungs of the two ladder-sections come on the same horizontal plane; also, inimproving the construction of this class of extension ladders, whereby their value will be materially enhanced and their strength and durability greatly increased. These several objects above enumerated are attained by the construction substantially as shown in the drawings, and hereinafter described and claimed.

Figure 1 of the drawings represents a front elevation of our improved ladder, partly in broken section; Fig. 2, a detail view, in perspective and upon an enlarged scale, of the device for supporting and holding the movable and extensible ladder-section in its adjusted position; Fig. 3, a vertical section, on an enlarged scale, taken on line 3 3 of Fig. 1, showing the device for sustaining or holding the extensible section in position and the rung resting in the U-shaped seat thereof; Fig. 4, a similar View showing the device raised by contact therewith of the rung of the extensible ladder-section; Fig. 5, a horizontal section taken on line, 5 5 of Fig. 1.

In the accompanying drawings, A represents what is termed the stationary laddersection, or the section which is to rest upon the ground or floor or other like support, and

consists of the usual side pieces a and con meeting-rungs b c, which are connected to the side pieces so that they will be opposite each other and on the same horizontal plane.

The side pieces a are of sufficient width so that when the rungs are secured thereto the required space will be left between the rungs b c to admit the extensible ladder-section B to freely move between them when raised or lowered. This extensibleladder-section consists of the usual side pieces 01 and rungs e, the same vertical space being left between said rungs as between the respective pairs of rungs b 0, so that when the extensible laddersection is adjusted the three rungs b c e will be on the same horizontal plane, and thereby present a wide tread for the foot- In order to conveniently raise or elevate the extensible ladder-section B, a suitable hoisting-rope f isprovided, one end of which is attached to the lower end of 'said section and the opposite end to one of the side pieces of the stationary ladder-section A. This hoisting-rope passes over a groovedpulley g, which has its bearings in the upper end of one of the side pieces of the ladder-section A, as shown in Figs. 1 and 3, and this side piece has a longitudinal groove h for the hoisting- I rope to work in,as shown in Fig. 5, thus forming a guide therefor and preventing frictional contact of the extensible ladder-section B against said rope when the same is moved up or down.

Any other preferred and well-known means may be provided for raising or elevating the extensible ladder-section, although the means shown is considered the most simple and practical; but we reserve the right to make such changes or modifications in the several details of construction as would come within ordinary mechanical skill, and this without departing from the principle of our invention.

The support 0 is especially constructed to firmly sustain the rung at both ends, so that said rung of the extensible ladder-section will be firmly supported and capable of hearing more weight and also enabling said rung to be disposed on the same horizontal plane with the respective pairs of rungs of the lower or stationary ladder-section, so as to present a wide tread. To attain this object, the sup port 0 is constructed of wire of the desired strength, and is bent to form a transverse horizontal connecting-bar 15, said bar at its ends being bent at right angles and also bent to form U-shaped seats 1'. It will be noticed that the transverse bar 15 is of sufiicient length to nearly equal thelength of the rungs e, and the U-shaped seats 1' are at the extremity or ends of the bar, thereby supporting the mug at both its ends and not at the center, thus giving greater sustaining power thereto. The transverse bar t also forms a longbearing when resting upon one ofthe rungs e, and consequently the sustaining power of the support 0 also increased, and by the employment of the: U-shaped seats therung when resting therein will be on the same horizontal plane witlrthe'rcspective pairs of rungs ofthe stationary or lower ladder-section.= Thethree rungs being thus on the same-horizontal plane, a wide tread for the foot is provided, and consequently the rung a does not receive the entire weight,-but, on the contrary, is distributed over-the three rungs and the pressure and weight materially taken oif the support.

The U-shaped seats 11 serve an additionalpurpose in presenting to therungs e as the ladder extension B is raised a roundedshouh der 7c,and as therungs'successively come in contact therewith .the support will be automatically raised until the rungs pass beyond the support, when the latter willfall by grav-' ityto its normal position ready to receive the runglimlnediately above it, and thus hold the extensible ladder-section-in its elevated position, the three rungs, as previously stated, he-

ingron the same horizontal plane to form a broad bearingor treadfor the feet,

The support 0 is bent to form laterally-extending arms I, which have their hearings in suitable eyeson upon the edge of i the side pieces a of the stationary ladder-section.

Anysuitable and well-known means may be employedfor pivoting the supportO to the stationary-1adder-section A; butthat shown is considered to be the most simple and effective.

One of the arms Z of the support 0 has a downward extension 07/, which terminates in an eyeo for engaging Withan eye 11 upon the upper end of an operating-rod D, said rod passing through guidesrupon one of the side pieces a of the ladder-section A. This operating-rod extends down a sufiicient distance to be in convenient reach of a person on the ground and has a suitable handle 3 at its lower extremity for operating it.

Having now fully described our invention, what we claim as new, and desire to secure by Letters Patent,is--

1. In an extension-ladder, a ladder-section having rungs arranged in pairs connected to the section upon opposite sides thereof and an extensible ladder-section located between the rungs formingthe pairs, incombination with a pivoted support consisting ofa transverse horizontal connecting-bar having at eachend a U-shapedseat to sustain the rung ofithe extensible ladder-sectionat both its ends and on the same plane with the rungs of therespective pairs, substantially as and for the purpose described;

2. In an extension-ladder, a having rungs arranged in pairsand connected thereto upon opposite sides andan extensible ladder-section located between the rungs forming the pairs, in combination with a piv- OiZQd WllB support consisting of a transverse connectingbar having a U-shaped seat at each end and operating-rodconnected to the support and a rope and pulley for raising the extensible ladder-section, substantially as and for the purposespecified.

In testimony whereofwe have hereunto set our respective hands in the presence of'two subscribing witnesses.

WM: J. ROBERTSGN." J. B. GENIN; \Vitnesses:

WIvLG. SHAW, ALBERT P. CRoss.

ladder-section 

